Fox and the show's producers FremantleMedia and 19 Entertainment released the following statement:

"Mariah Carey is a true global icon - one of the most accomplished artists on the planet - and we feel extremely fortunate that she was able to bring her wisdom and experience to the 'American Idol' contestants this season. We know she will remain an inspiration to 'Idol' hopefuls for many seasons to come."

Reilly also confirmed that the show would probably go back to three judges, the number it started with back in 2002.

Although the series is still one of the highest rated shows on broadcast TV, Season 12's ratings fell more than 20 percent over the previous season.

This season's finale earned a series low with a 3.6 rating, which was 44 percent down in the advertiser-coveted 18-49 demographic from last season's finale. It also fell to 14.3 million total viewers from last season's 21.5 million.

During the search to replace former judges Steven Tyler and Jennifer Lopez, executive producer Nigel Lythgoe hoped to create a genre-crossing panel that would draw new viewers to Season 12: Carey, a pop icon; Minaj, for her rap following; Urban for country. Those fans clearly didn't materialize.

Even early buzz surrounding a Carey-Minaj feud that broke out during open call auditions and carried on throughout the season didn't result in ratings. Instead, the Mariah and Nicki tension killed chemistry among the judges panel and drew focus away from the contestants.

Beyond the feud with Minaj, Carey's tenure with the competition was a bumpy one. She admitted on-air that producers had to speak with her about making her criticisms more constructive. Then, there was the report that producers plotted to replace her midseason with a returning Lopez in order to bump up the ratings.

An individual with knowledge of Fox's plans to overhaul the show told TheWrap, that the network feels the show has "lost their core audience and they want it back."